1. Field of the Invention
The present invention relates to a technique of feeding a piece of fabric formed as a tubular or a cylindrical shape to a sewing portion of a sewing machine as as to sew a hem portion of the fabric.
2. Description of the Prior Art
To perform the so-called lapped-edge stitching (see FIGS. 16A, 16B and 16C) using a hem-stitching sewing machine by means of a chain stitch, a fabric edge-lapping tool such as a twicefolding tool and a fabric edge detector have conventionally been provided at a position closer to the fabric feeding direction of the sewing portion of a sewing machine. The fabric edge-lapping tool is operated manually when inserting a piece of fabric so as to form a twice-folded, three-layered band 38, 39 (see FIGS. 16A, 16B and 16C) along one edge portion of the fabric. The fabric edge detector detects the edge of the fabric while feeding the fabric in such a way as to perform the so-called overlock stitching as the overcasting stitches accurately enwrap the thickness of the folded fabric portion and the outermost fabric end, and moves horizontally by intersecting at right angles the feeding direction of the fabric.
Accordingly, the fabric edge-lapping tool and the fabric edge detector do not serve as obstacles in the case of a flat-shaped piece of fabric. However, in the case of a cylindrically-shaped piece of fabric, and particularly when the diameter of the cylinder is small, for instance, the the case of the edge of a sleeve of a child's shirt, the fabric edge-lapping tool and the fabric edge detector serve as obstacles even if the sleeve is inserted around the cylindrically shaped bed of a so-called free arm sewing machine. It has been extremely difficult and practically impossible to feed the fabric and accurately perform overlock stiching while manually inserting the edge of fabric into the fabric edge-lapping tool and making the edge of the fabric three-layered.